Nevertheless, no alterations in the percentage of cells showing the inactivated phosphorylated version of Rb was observed either between BRAFV600E non-tumor areas and adenomas or between BRAFV600E and control mice (Supplementary Fig. 6B), thus suggesting that BRAFV600E-mediated p21CIP1 activation in the alveolar parenchyma may not rely on pRb/E2F axis. This evidence concerns the gene RB1 and neoplasm.